Use of polymerase chain reaction for the differentiation of Group A bovine rotavirus G6, G8, and G10 genotypes in the North Island of New Zealand

Prevalence of bovine rotavirus among cattle in mainland China: A meta-analysis

BACKGROUND

Bovine rotavirus is the primary pathogen causing diarrhea in cattle and can be transmitted vertically through the placenta. It mainly presents with clinical signs such as depression, loss of appetite, diarrhea, vomiting, and dehydration.

METHODS

A systematic review and meta-analysis were conducted to assess the prevalence of BRV infection in mainland China. We conducted a literature search on the prevalence of BRV infection in pigs between Jan 1, 1979 and Dec 31, 2021 in English and Chinese databases, including PubMed, Google Scholar, Cochrane library, Clinical Trials, VIP, CNKI, and WanFang database. Selections were made based on the title and the abstract of the paper, Search strings included if they reported the cattle samples of more than 15 cattle and provided information that allowed us to establish the prevalence of BRV. Moreover, we excluded repeated studies, reviews, other hosts. Finally, we extracted the number of cattle with BRV infection from the obtained studies and provided information that permitted us to estimate the prevalence of BRV infection in cattle in mainland China.

RESULTS

The data of 29 articles (including data on 10677 cattle) are compliant with the standards. The pooled prevalence of BRV in cattle in China was 46%（6635/10677）, the pooled prevalence of BRV in cattle from Northeast China (40%) was significantly lower than those from other regions. In addition, the prevalence of BRV was associated with publication time of paper, detection methods, age of cattle, and clinical symptoms（diarrhea, etc.).

CONCLUSION

Our findings suggest that BRV infection is common among cattle in China. It is, therefore, necessary to carry out further research and monitor the prevalence of BRV infection. Furthermore, powerful and effective regulatory measures should be taken to prevent the transmission and spread of BRV among cattle populations.

Risk factors for bovine rotavirus infection and genotyping of bovine rotavirus in diarrheic calves in Bangladesh

Bovine rotavirus (BRV) is considered the leading cause of calf diarrhea worldwide, including Bangladesh. In this study we aimed to identify risk factors for BRV infection and determine the G and P genotypes of BRV strains in diarrheic calves. Fecal samples were collected from 200 diarrheic calves in three districts between January 2014 and October 2015. These samples were screened to detect the presence of BRV using rapid test-strips BIO K 152 (RTSBK). The RTSBK positive samples were further tested by polyacrylamide gel electrophoresis and the silver staining technique to detect rotavirus dsRNA. Risk factors were identified by multivariable logistic regression analysis. The G and P genotypes of BRV were determined by RT-PCR and sequencing. A phylogenetic tree was constructed based on the neighbor-joining method using CLC sequence viewer 8.0. About 23% of the diarrheic calves were BRV positive. The odds of BRV infection were 3.8- (95% confidence interval [95% CI]: 1.0–14.7) and 3.9-times (95% CI:1.1–14.2) higher in Barisal and Madaripur districts, respectively, than Sirrajganj. The risk of BRV infection was 3.1-times (95% CI: 1.5–6.5) higher in calves aged ≤ 5 weeks than those aged >5 weeks. Moreover, the risk of BRV infection was 2.6-times (95% CI:1.1–5.8) higher in crossbred (Holstein Friesian, Shahiwal) than indigenous calves. G6P[11] was the predominant genotype (94.4%), followed by G10P[11] (5.6%). The BRV G6 strains were found to be closest (98.9–99.9%) to Indian strains, and BRV G10 strains showed 99.9% identities with Indian strain. The VP4 gene of all P[11] strains showed >90% identities to each other and also with Indian strains. The most frequently identified BRV genotype was G6P[11]. About 23% of calf diarrhea cases were associated with BRV. To control disease, high-risk areas and younger crossbred calves should be targeted for surveillance and management. The predominant genotype could be utilized as the future vaccine candidate or vaccines with the dominant genotype should be used to control BRV diarrhea in Bangladesh.

Cross-sectional study and genotyping of rotavirus-A infections in ruminants in Kuwait

Background

Group A rotaviruses (RVA) are zoonotic pathogens responsible for acute enteritis in human and neonatal ruminants. This research aimed to determine the prevalence of RVA in ruminants (cattle, sheep, and goats) and investigate the circulating RVA genotypes in these animals in Kuwait. We conducted a cross-sectional study to detect RVA in ruminants, using an immunochromatography test (IC), direct sandwich ELISA test, and real-time RT-PCR (RT-qPCR) assay using fecal samples.

Results

A total of 400 cattle, 334 sheep, and 222 goats were examined. The prevalence of RVA was 5.3, 1.2, and 2.3%, respectively, using IC. The ELISA test detected RVA from 4.3% of cattle, 0.9% of sheep, and 1.8% of goats. There was a significant association between the occurrence of diarrhea and the presence of RVA in bovine fecal samples (p-value = 0.0022), while no statistical association between diarrhea and the presence of RVA in fecal samples of sheep and goats was observed (p-value = 0.7250; p-value = 0.4499, respectively). Twenty-three of the IC-positive samples (17 from cattle, two from sheep, and four from goats) were tested using a RT-qPCR RVA detection assay targeting the NSP3 gene. The results showed that 21 of 23 IC-positive samples tested positive by RT-qPCR. Detection of RVA genotypes revealed that G10P[11] was the predominant strain in cattle (58.8%), followed by G8P[1] (11.7%). One sheep sample was genotyped as G8P[1]. In addition, G6P[1] and G6P[14] were detected in goat samples.

Conclusion

The present study revealed that the IC was more sensitive in detecting RVA antigen in fecal samples than the ELISA test. A higher occurrence of RVA infection was observed in cattle than in sheep and goats. This study suggests that RVA might be a risk factor of diarrhea in bovine calves less than 2 weeks old. This research also demonstrates the circulation of RVA in sheep and goat populations in Kuwait. Finally, the G10P[11] RVA genotype was the most prevalent genotype identified from cattle samples.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-021-02944-4.

The molecular epidemiology of bovine rotaviruses circulating in Iran: a two-year study

Bovine group A rotavirus (bovine RVA) is recognized as a major cause of severe gastroenteritis in newborn calves. The purpose of this study was to estimate the prevalence and identify the genotypes of circulating bovine RVA in newborn diarrheic calves. Two hundred fifty-three stool samples of diarrheic calves up to 1 month old were collected from 42 industrial dairy farms in two Iranian provinces during March 2010 to February 2012. All collected samples were screened for the presence of bovine RVA by RT-PCR, and the G and P genotypes were determined by semi-nested multiplex RT-PCR assay. The results of RT-PCR indicated that 49.4 % (125 out of 253) of the samples were positive for bovine RVA. The G and P genotyping of a subset of positive samples (n = 85) by semi-nested multiplex RT-PCR revealed that G6 (55.3 %) and G10 (43.5 %) and P[5] (51.8 %) and P[11] (27 %) were the most prevalent G and P genotypes, respectively. G6P[5] was the dominant genotype (35.3 %), followed by G10P[5], G10P[11] and G6P[11], with prevalence rates of 16.5 %, 15.3 % and 10.6 %, respectively. Sequence analysis of 20 VP7 and four VP4 genes showed highest nucleotide sequence identity with the corresponding genes of strains RVA/Cow-tc/GBR/UK/1973/G6P7[5] and RVA/Cow-tc/USA/B223/XXXX/G10P[11]. The results of this study reveal the diversity of G and P genotypes in bovine RVA samples from diarrheic Iranian calves and expands our knowledge of bovine RVA infections in the Middle East. These results also highlight the importance of producing of an effective rotavirus vaccine and its inclusion in the national cattle immunization program.

Prevalence of endemic enteropathogens of calves in New Zealand dairy farms

AIM

To conduct a country-wide prevalence study of bovine group A rotavirus, coronavirus, Cryptosporidium parvum, Salmonella spp. and enterotoxigenic K99(+) Escherichia coli (K99) in calves on New Zealand dairy farms.

METHODS

Faecal samples (n=1,283) were collected during the 2011 calving season from calves that were 1-5 and 9-21 days-old on 97 dairy farms, and were analysed for the presence of bovine group A rotavirus, coronavirus, Cryptosporidium and Salmonella spp., and K99. Farm-level prevalences were calculated and relationships between demographic variables and the presence of enteropathogens were examined using logistic regression models.

RESULTS

Of the 97 farms, 93 (96%) had at least one sample infected with enteropathogens. The standardised farm prevalences of bovine group A rotavirus, bovine coronavirus and C. parvum were 46, 14 and 18%, respectively, in calves that were 1-5 days-old, and 57, 31 and 52%, respectively, in calves that were 9-21 days-old. The farm-level prevalence of K99 was 11% in calves that were 1-5 days-old. Salmonella spp. were found in three and four samples, from calves that were 1-5 and 9-21 days-old, respectively. No associations between explanatory variables and the presence of the enteropathogens were identified at the farm level. At the calf level, the odds of C. parvum shedding and of co-infection with any combination of pathogens were greater in calves that were 9-21 than 1-5 days-old.

CONCLUSIONS AND CLINICAL RELEVANCE

This study provides epidemiological estimates of the prevalence of calves' enteropathogens in New Zealand, which could be used for infection risk assessment or estimation of the environmental loads of pathogens shed in cattle faeces.

Molecular characterization of the NSP4 gene of human group A rotavirus strains circulating in Tunisia from 2006 to 2008

Non-structural protein 4 (NSP4), encoded by group A rotavirus (RVA) genome segment 10, is a multifunctional protein and the first recognized virus-encoded enterotoxin. Recently, a new classification system for RVAs was proposed and a total of 14 NSP4 genotypes (E1-E14) are currently described. The most common NSP4 genotypes in humans are Wa-like E1 and DS-1-like E2. This report represents the first investigation on the genetic diversity of RVA NSP4 genes in Tunisia from 2006 to 2008. In the present study, the NSP4-encoding genes of human RVA strains with different G/P-genotype combinations were analyzed. NSP4 genes of 261 RVA-positive fecal samples were analyzed using a semi-nested reverse transcriptase-polymerase chain reaction and in addition the NSP4 gene of 46 representative RVA strains were sequenced. Phylogenetic analysis of the Tunisian NSP4 nucleotide sequences revealed the presence of two NSP4 genotypes. Genotype E1 was found to be associated with G1P[8], G3P[6], G3P[8], G4P[6] and G4P[8], whereas genotype E2 was associated with G2P[4], G2P[6] and G6P[9] samples. These results support the hypothesis that P[8] carrying RVA strains usually possess the E1 genotype, whereas P[4] carrying RVA strains usually possess the E2 genotype. P[6] carrying strains were found with both E1 and E2. The unusual G6P[9] strains possessed a E2 genotype with a possible animal origin. These results underline the need for further investigations to assess the validity of NSP4 as a suitable target for epidemiologic surveillance of RVA infections and vaccine development.

Detection of the first G6P[14] human rotavirus strain from a child with diarrhea in Egypt

We report the first detection of a G6P[14] rotavirus strain in Egypt from the stool of a child participating in a hospital-based diarrhea surveillance study conducted throughout the year 2004. Rotavirus infection was initially detected using a rotavirus group A VP6 enzyme immunoassay; the P (VP4) and G (VP7) genotypes of the strain were identified by RT-PCR. We sequenced the VP7 gene and the VP8* portion of the VP4 gene and the strain displayed the strongest identity to the VP7 [>94% nucleotides (nt), >97% amino acids (aa)] and VP4 (>93% nt, >98% aa) sequences of PA169, a novel G6P[14] strain first isolated from a child in Italy during the winter of 1987. Additional sequencing and analysis of the other remaining structural (VP1-VP3, VP6) and non-structural (NSP1-NSP5) proteins support this animal-to-human reassortment theory. According to the full genome classification system, the G6P[14] strain (EGY3399) was assigned to G6-P[14]-I2-R2-C2-M2-A11-N2-T6-E2-H3 genotypes. The greatest similarity of EGY3399 NSP4 and NSP5 gene sequences were to those of ovine and simian origin, respectively. Coupled with other observations, our results suggest G6P[14] isolates rarely cause severe diarrhea in Egyptian children, and support other studies that indicate animal rotavirus contribute to the genetic diversity of rotavirus detected from humans through interspecies transmission and single or multiple segments reassortment.

Diversidade genotípica de rotavírus suínos no Estado de São Paulo

Rotavírus é uma das causas mais comuns de diarréia tanto em humanos quanto em diferentes espécies animais. Foi conduzido um estudo transversal a partir de 144 amostras fecais diarréicas colhidas de leitões, provenientes de 16 criações comerciais distribuídas por 10 municípios do Estado de São Paulo, Brasil, com o objetivo de se detectar a ocorrência de rotavírus e realizar sua caracterização molecular quanto seus genotipos G e P. Um total de 43 amostras (29,86%) foram positivas para rotavírus por Eletroforese em Gel de Poliacrilamida (PAGE) e ELISA, num esquema de triagem em paralelo. A caracterização mediante reações do tipo nested-multiplex RT-PCR demonstrou que, isoladamente, o genotipo P[6] foi o mais frequente, detectado em 25,58% das amostras, seguido pelo P[1] (11,63%) e P[7] (9,3%). Infecções concomitantes de genotipos P[6]+P[7] (9,3%), P[1]+P[6] (4,65%), P[1]+P[6]+P[7] (2,33%) foram também observadas. Analogamente, o genotipo G[5] foi detectado em 30,23% das amostras, seguido pelo G[10] (20,93%) e G[6] (4,65%) e G[5]+G[10] (18,6%). O genotipo G[5]P[6] foi o mais frequente (11,63%), porém outras combinações e amostras não tipificáveis também foram observadas. Considerando-se a diversidade de rotavírus suínos encontrada na população estudada, medidas profiláticas específicas devem levar em conta, para sua efetividade, o grau de proteção cruzada entre os genotipos presentes nas formulações vacinais e aqueles que realmente são circulantes numa região.